UFC Filter Holder 1¼" AUX (requires #2459113)

I have assembled the UFC filter slider with the 1 1/4" AUX filter holder. There does seem a way of securing the holder in the slider. I noticed that the 50.4mm uses the three screws into the slider to prevent it moving. Is there another part, such as a cover plate, that will hold the AUX holder in place using the screws from the slider ? Otherwise all the components are working well, thank you.